The Coalition for HIV Vaccine Development (CHVD) is a partnership of highly experienced basic vaccinologists and clinical vaccine researchers of the Center for Vaccine Development and the Institute of Human Virology of the University of Maryland. CHVD focuses on basic, translational and clinical vaccine research, including bringing new candidate vaccine approaches from bench to bedside, such as the first generation Salmonella-vectored HIV vaccine. CHVD investigators have an extensive track record of leadership in multicenter collaborative trials. The tight interface between basic and clinical vaccinology, intrinsic to CHVD's structure, facilitates a major goal of the HIV Vaccine Trials Network (HVTN), to expand the pool of HIV vaccine candidates and strategies. This application details the current clinical research capacity of the CHVD Clinical Trials Unit (CTU) to conduct Phase I, II and III HIV vaccine trials. The CHVD CTU currently integrates a consortium of clade B sites in the Baltimore-Washington area and in the Caribbean (current HIVNET site in Trinidad). Represented in this consortium of sites are low risk populations of different ages and races, and of varied socioeconomic, behavioral and genetic background suitable for Phase I and early Phase II trials. High-risk populations available for advanced Phase II and Phase III trials are anchored by a large high risk heterosexual population in the Caribbean, and domestically includes persons at high-risk through injection drug use and discordant heterosexual and homosexual partnership. This homologous clade B consortium of sites not only enriches the HVTN scientific capacity to evaluate clade B derived vaccines, but non-clade B products for critical cross protection studies as well. Furthermore, the proximity of these international locales provides an optimal environment for enriching the laboratory-based agenda of the HVTN by facilitating timely access of fresh biologic specimens from vaccinees to the central and special emphasis group laboratories of the network.